let width=3.2;
let name='张三';
let varchar=width+name;
console.log(typeof varchar);

let boolean=true;
let varchar2=width+boolean;
console.log(typeof varchar2);

let varchar3=boolean+name;
console.log(typeof varchar3);

let varchar4=name*width;
console.log(typeof varchar4);

let varchar5=name/width;
console.log(typeof varchar5);

let width2=10;
let height=20;
let area=width2*height;
console.log('宽为'+width2+'厘米高为'+height+'厘米的矩形面积为：'+area+'平方厘米');

const PI=3.1415926;
let radius=5;
let area2=PI*radius*radius;
console.log('半径为'+radius+'厘米的圆的面积为'+area2+'平方厘米');
